Thin film light emitting diode

Abstract

Light emitting LEDs devices comprised of LED chips that emit light at a first wavelength, and a thin film layer over the LED chip that changes the color of the emitted light. For example, a blue LED chip can be used to produce white light. The thin film layer beneficially consists of a florescent material, such as a phosphor, and/or includes tin. The thin film layer is beneficially deposited using chemical vapor deposition.

1. A light emitting diode (LED), comprising:
 an LED chip having a first electrical contact and a second electrical contact, the LED chip emitting blue light having a first wavelength in response to applied electrical power; and  
 a thin film layer over the LED chips;  
 a passivation layer between the thin film layer and the LED chip, wherein the thin film layer is prevented from directly contacting the LED chip;  
 wherein the thin film layer and the blue light interact to form light having a second wavelength.  
 
   
   
     2. An LED according to  claim 1 , wherein the thin film layer includes at least one of phosphor and tin. 
   
   
     3. An LED according to  claim 1 , further comprising a second passivation layer over the thin film layer. 
   
   
     4. An LED according to  claim 1 , wherein the thin film layer and the blue light interact to form white light. 
   
   
     5. An LED according to  claim 1 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact. 
   
   
     6. An LED according to  claim 1 , wherein the LED chip has a lateral topology structure. 
   
   
     7. An LED according to  claim 6 , wherein the LED chip includes:
 a substrate;  
 an n-type GaN structure on a surface of the substrate;  
 an active layer having at least one quantum well on the n-GaN structure;  
 a p-type GaN layer on the active layer;  
 a transparent conductive layer on the p-type GaN layer;  
 a p-type electrical contact on the transparent conductive layer; and  
 an n-type electrical contact on the n-type G 3 aN structure.  
 
   
   
     8. An LED according to  claim 7 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact. 
   
   
     9. An LED according to  claim 7 , wherein the n-type GaN structure includes an n-type GaN buffer layer. 
   
   
     10. An LED according to  claim 7 , wherein the substrate includes sapphire. 
   
   
     11. An LED according to  claim 1 , wherein the LED chip has a vertical topology structure. 
   
   
     12. An LED according to  claim 11 , wherein the LED chip includes:
 an n-type GaN structure;  
 an n-type electrical contact adjacent a surface of the n-type GaN structure;  
 an active layer having at least one quantum well on the n-type GaN structure;  
 a p-type GaN layer on the active layer;  
 a transparent conductive layer on the p-type GaN layer; and  
 a p-type electrical contact on the transparent conductive layer.  
 
   
   
     13. An LED according to  claim 12 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact. 
   
   
     14. An LED according to  claim 12 , wherein the n-type GaN structure includes an n-type GaN buffer layer. 
   
   
     15. An LED according to  claim 1 , wherein the passivation layer includes SiO 2 . 
   
   
     16. An LED according to  claim 1 , wherein the passivation layer includes Si x N y . 
   
   
     17. An LED according to  claim 1 , further including a package environmentally protecting the LED chip. 
   
   
     18. A light emitting diode (LED), comprising:
 an LED chip having a first electrical contact and a second electrical contact, the LED chip emitting light having a first wavelength in response to an applied electrical power; and  
 a thin film layer over the LED chip, wherein a passivation layer is interposed between the thin film layer and the LED chip;  
 wherein the thin film layer converts the light of the first wavelength to a light of second wavelength.  
 
   
   
     19. An LED according to  claim 18 , wherein the thin film layer includes a fluorescent material. 
   
   
     20. An LED according to  claim 18 , further comprising a second passivation layer over the thin film layer. 
   
   
     21. An LED according to  claim 18 , wherein the light of the second wavelength is white light. 
   
   
     22. An LED according to  claim 18 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact. 
   
   
     23. An LED according to  claim 18 , wherein the LED chip has a lateral topology structure. 
   
   
     24. An LED according to  claim 18 , wherein the LED chip has a vertical topology structure.